My U.S. Pat. No. 5,217,681, issued Jun. 8, 1993, discloses a prestressed pressure vessel safety enclosure used as a pressure safety enclosure for a nuclear reactor pressure vessel or other primary system vessel containing fluid or gaseous material under high pressure. The special pressure vessel enclosure comprises a first pressure vessel containment assembly surrounding the primary pressure vessel. A pair of first upper and lower pressure vessel jackets are adapted to enclose and be spaced apart, respectively, from the upper and lower portions of the first pressure vessel containment assembly with the rims of the jackets adapted to be slidable and sealed with respect to the first pressure vessel containment assembly. The spaces between the jackets and pressure vessel containment assembly are filled with a high boiling point, low melting point metal.
Upper and lower ring girders, connected to each other by tension tendon members, in conjunction with upper and lower jacket bearing plates and skirts are used to apply force to the respective upper and lower jackets for moving the jackets toward or away from each other.
My U.S. Pat. No. 5,465,280, issued Nov. 7, 1995, discloses a nuclear reactor vessel employing bellows in the construction thereof which operate as fluid barriers, confine lead material filler, and allow for relative movement of structural components of the apparatus in a controlled manner. Additionally, the apparatus disclosed in U.S. Pat. No. 5,465,280 incorporates connector tendons of a specialized construction, incorporating two sets of tendons, one of which is prestressed almost to yield point, and the other of which is prestressed to a lesser degree.
U.S. Pat. No. 5,204,054, issued Apr. 20, 1993, discloses a nuclear reactor system pressure vessel comprising a steel inner liner part, an intermediate insulative layer part and an outer concrete encasing part pre-stressed by cable tendons located inside the casing. Use of the pre-stressed construction allows for construction of pressure vessels of larger size. The outer vessel part can be of a cast single piece structure or it can be an integrated concrete segment assembled structure embodying pre-stressing cable tendons arranged in various orientations to effect pre-stressing. Further, the major portion of the pressure vessel can be disposed below grade to lessen the presence of vessel structure in a nuclear system containment. Cooling passages are provided in the pressure vessel to carry off reactor decay heat as well as heat in the concrete outer vessel part.
Applicant is aware of a publication entitled Recent Investigations and Tests With the BBR Winding System for Circumferential Prestressing of Concrete Vessels and Containments authored by K. Schutt and F. E. Speck, published in 1993 by Elsevier Science Publishers B. V. in SMiRT-12 Transactions. The publication discloses the use of elongated reinforcement elements in the form of continuously wound prestressing wire strands or bands which are wound about the periphery of large prestressed concrete pressure vessels for nuclear power stations. The prestressed strands are applied in layers spirally wound over the whole width of channels formed at the outer periphery of the concrete pressure vessel, requiring much less space and making them easier to install and inspect compared to cable tendons.
The following publications and United States patents are also believed to be representative of the state of the prior art: U.S. Pat. No. 3,433,382, issued Mar. 18, 1969, U.S. Pat. No. 3,775,251, issued Nov. 27, 1973, U.S. Pat. No. 4,192,718, issued Mar. 11, 1980, U.S. Pat. No. 3,445,971, issued May 27, 1969, U.S. Pat. No. 3,512,675, issued May 19, 1970, U.S. Pat. No. 3,653,434, issued Apr. 4, 1972, U.S. Pat. No. 3,606,715, issued Sep. 21, 1971, U.S. Pat. No. 5,229,067, issued Jul. 20, 1993, U.S. Pat. No. 5,047,201, issued Sep. 10, 1991, U.S. Pat. No. 4,859,402, issued Aug. 22, 1989, U.S. Pat. No. 4,650,642, issued Mar. 17, 1987, and U.S. Pat. No. 4,032,397, issued Jun. 28, 1977.
Applicant has authored a paper entitled Prestressed Safety Enclosure (PSE) with Metallic Cushion for New or Existing Reactor Pressure Vessels, published in SmiRT 11 Transactions Vol. SD2 (August, 1991).